1. Field of the Invention
The present invention generally relates to a system and method for measuring the refractive index and the thickness of a lens, in particular to a system and method for nondestructively measuring the refractive index and the thickness of a lens.
2. Description of the Related Art
Nowadays, the rapid development in science and technology in the world has lead to the high demand of the optical products. The related commercial optical products or consumer electronics include digital cameras, cell-phone cameras, solid immersion lens, telescopes, microscopes and the like. On the contrary, technology development relies on fast and accurate measurement and manufacture of optical components. Therefore, the size of the electro-optic system could be reduced and the quality of the captured image thereof could be raised. The most important properties of the optical components are their refractive indices and thickness. Conventionally, the thickness of the transparent lens can be measured by the mechanical caliper. On the other hand, in order to measure the refractive index of the transparent lens, the lens sample must be cut to a square, plate or prism in shape at first and then the refractive index of the cut lens sample can be measured by a v-block refractometor, spectral goniometer, spectroimeter and the like.
With reference to FIG. 1 for the schematic view of the conventional measurement method. As shown in FIG. 1, the lens sample is cut to a prism and then the refractive index thereof can be obtained according to the following formula:
      n    =                  sin        ⁢                              α            +            β                    2                            sin        ⁢                  α          2                      ;wherein the minimum deviation angle of the prism is designated by β.
With reference to FIG. 2 for the schematic view of the conventional measurement method. As shown in FIG. 2, the lens sample is cut to a 20×20×5 mm3 prism and then the refractive index thereof can be determined by the v-block refractometor. Accordingly, the conventional measurement methods are considered to be destructive methods, which are not efficient and high-cost. Moreover, the aforementioned method is conducted to a limited lens sample size of about 20×20×5 mm3, which cannot be applied to the micro-lens.